1. Field of the Invention
The present invention relates to a winged safety needle assembly and, more particularly, to a winged safety needle assembly having a winged cylindrical sheath for substantially reducing sticking accidents from taking place when retracting the needle into the winged cylindrical sheath. Protection of the edge of the needle is achieved by unlocking and sliding the needle along the inner wall of the winged cylindrical sheath.
2. Discussion of the Related Art
Proper disposal of used needles is required to avoid needlestick injuries. Used needles may be recapped with the same cover that originally covered the needles before use or by similar covers or tubes before the needle is discarded. This method requires movement of the hands toward the exposed needle and may promote needlestick injuries during the recapping. In addition, needles may also be disposed of by tossing them into nearby refuse containers. However, this creates danger to those who handle the refuse containers.
Winged intravenous (IV) sets are well known in the art. A typical prior art IV butterfly needle used for the insertion into blood vessels and similar passageways in the body to permit the infusion or withdrawal of sterile fluids or blood is illustrated in FIG. 8a and FIG. 8b. The butterfly needle generally has a hollow needle or cannula 30, a cylindrical hub 20 holding the needle 30 at one end and connected to an IV tube 52 at the opposite end, and a cylindrical housing 10 surrounding the needle with a wing-like extension 50 extending on each side thereof.
The wings 50 are used to handle the assembly during insertion and withdrawal. For example, the wings of the needle assembly may be folded upwards around the hub to provide a gripping extension for the technician or nurse to use when attempting to insert the needle into the desired vein, artery or other passageway. The wings are also used to stabilize the device while in place by providing a broad surface area of contact with the patient which allows for taping of the device to the patient while discouraging movement, especially rotation, of the device. This assists the technician or nurse in affixing the needle to the patient during the infusion of fluids or medicants.
A problem typical of butterfly needles as just described is that when the needle is withdrawn from the vein or artery, the sharpened end, now contaminated with blood or other body fluid, remains exposed. The exposed needle can be a source of great danger to the operator or to anyone who might be pricked or scratched. Needle injuries may result in the transmission of diseases such as hepatitis, HIV, or cause other types of infection. A common solution available to the operator was to simply drop the needle and the holder into a trash receptacle. However, a danger to clean up and medical waste disposal personnel continues if the used needles are not rendered harmless in some way. Another solution is to attempt to recap the needle with a safety cover immediately after use. This, however, may in itself cause injury if the operator should accidentally stick themselves during the recapping process. In addition, caps or covers may come loose and expose the used needle.
Therefore, in order to substantially reduce such sticking accidents various proposals have been made. One such proposal is a winged needle assembly disclosed in U.S. Pat. No. 5,505,711 (hereinafter referred to as the '711 patent). The '711 patent describes an indwelling injector needle assembly having wings including a cannula or needle body, a hub supporting a proximal end of the needle body, a tube in fluid communication with the needle body, a cylindrical holder having a distal end from which the wings protrude, and a latching mechanism. The hub can slide along an inner periphery of the holder between a first position near the distal end of the holder and a second position near a proximal end of the holder. The latching mechanism is formed in and disposed between the hub and the holder so that the hub is inhibited from moving from the first position toward the second position, and vice versa. The needle edge can be retracted within the holder while the wings remain fixed to a patient's skin.
However, the winged needle assembly disclosed in the '711 patent has a key disadvantage. The '711 patent discloses a structure that includes a non-rotating needle. A rotatable needle is preferable in order to maximize blood or fluid flow to or from a vessel in which the needle is inserted. The structure of the '711 patent prevents the needle from being rotated after cannulation. The '711 patent also describes a hub supporting the non-rotating needle. The hub has a guide groove formed in a peripheral wall thereof, the groove extending longitudinally of the hub. A cylindrical holder having wings is disposed on the hub. The cylindrical holder has a lug protruding inwardly from an inner peripheral surface of a proximal end thereof. The lug is slidably engaged with the guide groove in the hub so that the hub can be moved relative to the holder between a first position in which the needle body protrudes from a distal end of the cylindrical holder and a second position in which the needle body is retracted so that a pricking edge of the needle body is within the holder. The needle and hub cannot rotate relative to the cylindrical holder due to the lug being slidably engaged with the guide groove in the hub. Therefore the needle cannot be rotated when needed after cannulation in order to maximize blood or fluid flow to or from the vessel.
As can be seen, what is needed is a winged safety needle device that allows for rotation of the needle after cannulation in order to maximize blood or fluid flow to or from the vessel, and provides for a reliable and user friendly first releasable locking mechanism in an insertion position and a second unreleaseable locking mechanism in a protected position.